Missing-letter Effect Research Articles

Aural and written language elicit the same processes: Further evidence from the missing-phoneme effect.

When readers are asked to detect a target letter while reading for comprehension, they miss it more frequently when it is embedded in a frequent function word than in a less frequent content word. This missing-letter effect has been used to investigate the cognitive processes involved in reading. A similar effect, called the missing-phoneme effect has been found in aural language when participants listen to the narration of a text while searching for a target phoneme. In three experiments, we tested the hypothesis that both effects derived from the same cognitive processes, by isolating the role of word frequency and word function. In Experiment 1, we used a paper and pencil procedure for reading and a continuous narration for the listening task. In Experiments 2 and 3, we used a rapid serial visual or auditory presentation procedure to control for the effects of preprocessing upcoming information: parafoveal processing in reading and coarticulation in aural language processing. Parallel findings were observed in the reading and listening tasks. In all experiments, there was an effect of word function, and there was an effect of word frequency in Experiments 1 and 3. Results are interpreted in light of the attentional disengagement model. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Is the Missing Letter Effect Due Primarily to the Test Word Containing the Target Letter or to the Surrounding Words?

Abstract A simple letter detection task, in which subjects mark instances of a target letter in prose passages, has elucidated numerous cognitive processes involved in reading by examining the “missing letter” effect, in which readers’ detection accuracy is especially low on frequent function words. Two experiments explore the fundamental but novel issue of whether the missing letter effect is due to the test word containing the target letter or to the words surrounding the test word. College students searched for a target letter (e in Experiment 1, o in Experiment 2) in a passage that included unrelated sentences, with each sentence containing a single instance of 1 of 2 test words (the or one in Experiment 1, of or on in Experiment 2). The sentences were intact (prose), or the words in each sentence were randomly rearranged (scrambled). The 2 test words in an experiment were surrounded by the exact same words. If the word containing the target letter is primarily responsible for the missing letter effect, the proportion of correct letter detection responses should depend on the test word, whereas if the surrounding words are primarily responsible, it should depend on the text type (prose, scrambled). In fact, in both experiments a huge effect of test word was found but no effect of text type. These results provide clear evidence for the influence of the test word but, surprisingly, no evidence for the influence of the surrounding words on the missing letter effect in the letter detection task.

The Development of the Missing-Letter Effect Revisited.

When participants read a text for comprehension while identifying a target letter, the letter is more often missed in a frequent function word than in a less frequent content word. This is the missing-letter effect. Studies have shown the importance of both frequency and word function. The role of each of these factors in development is less understood. The goal of this study was to revisit the influence of frequency and word function in the missing-letter effect in development with better-controlled stimuli. Two hundred sixteen participants took part in this study and were divided into five groups (6-7 years, 8 years, 9 years, 10-11 years, and university students). They were asked to read four experimental texts for comprehension and to circle a target letter. The results showed a basic missing-letter effect with more omissions for a frequent function word than a less frequent content word for every group. When frequency was controlled, we found a word function effect as early as 6-7 years of age, with more omissions for a function word than a content word. In contrast, when word function was controlled, an effect of frequency was only significant for adults and 8-year-olds. These results clarify discrepancies in the literature and support the importance of rigorous stimuli control.

The missing-colour effect: The attentional beam captures reading-relevant and reading-irrelevant information.

According to many models, reading is driven by an attentional beam. In two experiments, we investigated the specificity of the beam by testing its sensitivity to a reading-irrelevant feature: colour. More specifically, participants were asked to read either a black-and-white version or a multi-colour version of the text in which each letter was printed in a different colour. In addition, while reading for comprehension, participants either searched for a target letter (t or d) or for a colour (pink or black). In Experiment 1, we used the Nelson-Denny reading test and in Experiment 2, we used an experimental text. In both the experiments, the typical missing-letter effect was observed with letters: Participants missed more letters in function than in content words. Most importantly, although the effect was smaller, this pattern of results was also observed when participants searched for a colour (e.g., pink or black letters in a multi-coloured passage). Our results suggest that the attentional beam involved in reading is sensitive to both reading-relevant and reading-irrelevant information.

The impact of familiarization strategies on the missing-letter effect.

When reading a text and searching for a target letter, readers make more omissions of the target letter if it is embedded in frequent function words than if it is in rare content words. While word frequency effects are consistently found, few studies have examined the impacts of passage familiarity on the missing-letter effect and studies that have present conflicting evidence. The present study examines the effects of passage familiarity, as well as the impacts of passage familiarization strategy promoting surface or deep encoding, on the missing-letter effect. Participants were familiarized with a passage by retyping a text, replacing all common nouns with synonyms, or generating a text on the same topic as that of the original text, and then completed a letter search task on the familiar passage as well as an unfamiliar passage. In Experiment 1, when both familiar and unfamiliar passages use the same words, results revealed fewer omissions for the retyping and synonyms conditions. However, in Experiment 2, when different words are used in both types of texts, no effect of familiarization strategy was observed. Furthermore, the missing-letter effect is maintained in all conditions, adding support to the robustness of the effect regardless of familiarity with the text.

What a Simple Letter-Detection Task Can Tell Us About Cognitive Processes in Reading

Understanding reading is a central issue for psychology, with major societal implications. Over the past five decades, a simple letter-detection task has been used as a window on the psycholinguistic processes involved in reading. When readers are asked to read a text for comprehension while marking with a pencil all instances of a target letter, they miss some of the letters in a systematic way known as the missing-letter effect. In the current article, we review evidence from studies that have emphasized neuroimaging, eye movement, rapid serial visual presentation, and auditory passages. As we review, the missing-letter effect captures a wide variety of cognitive processes, including lexical activation, attention, and extraction of phrase structure. To account for the large set of findings generated by studies of the missing-letter effect, we advanced an attentional-disengagement model that is rooted in how attention is allocated to and disengaged from lexical items during reading, which we have recently shown applies equally to listening.

The Missing-Phoneme Effect in Aural Prose Comprehension

When participants search for a target letter while reading for comprehension, they miss more instances if the target letter is embedded in frequent function words than in less frequent content words. This phenomenon, called the missing-letter effect, has been considered a window on the cognitive mechanisms involved in the visual processing of written language. In the present study, one group of participants read two texts for comprehension while searching for a target letter, and another group listened to a narration of the same two texts while listening for the target letter’s corresponding phoneme. The ubiquitous missing-letter effect was replicated and extended to a missing-phoneme effect. Item-based correlations between the reading and listening tasks were high, which led us to conclude that both tasks involve cognitive processes that reading and listening have in common and that both processes are rooted in psycholinguistically driven allocation of attention.

Evaluating missing-letter effects and comprehension in proficient and nonproficient languages

ABSTRACTThis study was conducted to examine whether word recognition and comprehension processes change as a function of language proficiency. Participants were highly proficient in English but at a low proficiency level in Spanish. The participants read texts presented in English and Spanish while reading normally or while performing a letter-detection task and then answered comprehension questions that tested their mental representations of the surface form, text base, and situational model. Overall letter-detection error rates were lower when texts were presented in the nonproficient Spanish language. There was a typical missing-letter effect in English, such that more detection errors were made on function than content words. In Spanish, the missing-letter effect was reversed, with more errors on content than function words. Overall comprehension was substantially better when reading English passages than Spanish passages and best at the situation model level. For the English passages, comprehension was reduced during letter detection compared to normal reading. For the Spanish passages, comprehension was similar for letter detection and normal reading. Question type did not systematically vary as a function of language proficiency or task type. These findings highlight differences in cognitive processes during reading as a function of language proficiency and enhance our understanding of the letter-detection task itself.

Are Letter Detection and Proofreading Tasks Equivalent?

When readers search for misspellings in a proofreading task or for a letter in a letter detection task, they are more likely to omit function words than content words. However, with misspelled words, previous findings for the letter detection task were mixed. In two experiments, the authors tested the functional equivalence of both tasks. Results reveal similar patterns of omissions for both search tasks when misspellings were produced by substituting one letter for another: There were more omissions for function words than for content words. However, when two letters were transposed, differences between the two tasks emerged. It is possible to conclude that letter detection and proofreading are based on common cognitive processes but the nature of the target can modulate the effects. Results are interpreted in light of the attentional disengagement model and the guidance organization model of the missing-letter effect.

Detecting letters and words in prose passages: a test of alternative theoretical accounts of the missing letter effect.

College students searched for either h or the in prose passages in which every h occurred in the test word the. In Experiment 1, passage versions differed in that the critical noun phrases were either the alone (i.e., in citation form as a noun referring to itself) or "the definite article." Many more detection errors occurred for letter than word target items, especially with "the definite article." In Experiment 2, passage versions differed in that a given noun phrase containing the test word the occurred as a subject in one version and an object in the other. Again, many more detection errors occurred when the target item was the letter h than when it was the letter sequence the. Also, with letter but not letter sequence targets, more detection errors occurred for object than subject noun phrases. In Experiment 3, passages were presented either in regular format or with all capital letters. Students made more detection errors with the regular than with the capitals format, many more errors occurred when participants searched for letters than for letter sequences, and the effect of target item was larger with regular than with capitals format. These findings suggest that accounts of detection errors in reading must include the influence of unitization and processing time or attentional allocation.

Mind wandering in text comprehension under dual-task conditions

In two experiments, subjects responded to on-task probes while reading under dual-task conditions. The secondary task was to monitor the text for occurrences of the letter e. In Experiment 1, reading comprehension was assessed with a multiple-choice recognition test; in Experiment 2, subjects recalled the text. In both experiments, the secondary task replicated the well-known “missing-letter effect” in which detection of e's was less effective for function words and the word “the.” Letter detection was also more effective when subjects were on task, but this effect did not interact with the missing-letter effect. Comprehension was assessed in both the dual-task conditions and in control single-task conditions. In the single-task conditions, both recognition (Experiment 1) and recall (Experiment 2) was better when subjects were on task, replicating previous research on mind wandering. Surprisingly, though, comprehension under dual-task conditions only showed an effect of being on task when measured with recall; there was no effect on recognition performance. Our interpretation of this pattern of results is that subjects generate responses to on-task probes on the basis of a retrospective assessment of the contents of working memory. Further, we argue that under dual-task conditions, the contents of working memory is not closely related to the reading processes required for accurate recognition performance. These conclusions have implications for models of text comprehension and for the interpretation of on-task probe responses.

Sex differences in the missing-letter effect: A question of reading or visual–spatial skills?

When readers must search for a target letter while reading a continuous text, they are more likely to miss targets in frequent function words than in less frequent content words. This missing-letter effect has been found across many languages, methodologies, and types of reading materials. Despite the ubiquity of the missing-letter effect, sex differences have been reported, but their pattern is conflicting and no clear interpretation has been offered so far. In two experiments, sex differences were examined in the letter search task, while also measuring spatial and reading skills. In both experiments, the missing-letter effect was found for both genders and a larger missing-letter effect was found for faster readers. It is concluded that when sex differences are observed in the missing-letter effect, they are likely due to reading speed and not to spatial skills as previously hypothesized. Results are interpreted in light of the Attentional Disengagement model of the missing-letter effect.

Eye movements when reading: The importance of the word to the left of fixation

In reading, it is well established that word processing can begin in the parafovea while the eyes are fixating the previous word. However, much less is known about the processing of information to the left of fixation. In two experiments, this issue was explored by combining a gaze-contingent display procedure preventing parafoveal preview and a letter detection task. All words were displayed as a series of xs until the reader fixated them, thereby preventing forward parafoveal processing, yet enabling backward parafoveal or postview processing. Results from both experiments revealed that readers were able to detect a target letter embedded in a word that was skipped. In those cases, the letter could only have been identified in postview (to the left of fixation), and detection rate decreased as the distance between the target letter and the eyes' landing position increased. Most importantly, for those skipped words, the typical missing-letter effect was observed with more omissions for target letters embedded in function than in content words. This can be taken as evidence that readers can extract basic prelexical information, such as the presence of a letter, in the parafoveal area to the left of fixation. Implications of these results are discussed in relation to models of eye movement control in reading and also in relation to models of the missing-letter effect.

Is Familiarity the All-Purpose Reading Tool? The Case of the Missing-Letter Effect for Self-Generated Texts

Participants performed a letter detection task on a self-generated and on an unfamiliar text to address two questions: Will letter processing differ for self-generated and unfamiliar texts? Is the missing-letter effect immune from text familiarity? The 36 participants were asked to write an essay and then to read it along with an unfamiliar text written by another participant while searching for a target letter. Results revealed the usual missing-letter effect for both familiar and unfamiliar texts and an effect of familiarity with fewer omissions for familiar than for unfamiliar texts. Results are interpreted in light of the Attentional-Disengagement model of the missing-letter effect.

How does dissociation between written and oral forms affect reading: evidence from auxiliary verbs in Arabic

In Arabic, auxiliary verbs are necessary in the written language, but absent from the oral language. This is contrary to languages such as English and French in which auxiliary verbs are mandatory in both written and oral languages. This fact was exploited to examine if dissociation between written and oral forms affects reading measures like letter detection task and therefore to validate the phenomenon of the missing‐letter effect (MLE) and to replicate previous studies. In addition, the study examined whether auxiliary verbs in Arabic are considered as functional elements that constitute part of the structural frame. Sixty native Arabic speakers read a passage while looking for a target letter that was embedded in a preposition, an auxiliary verb or a content word. Results showed the typical MLE with more omissions for the preposition than for the content words. However, the results with the auxiliary verb are less clear. The functional and the syntactic roles of auxiliary verbs in Arabic are discussed.

Evolution of the missing-letter effect among young readers between ages 5 and 8

ABSTRACTIn light of the numerous studies on the detection of target letters among adults, it is generally accepted that the missing-letter effect depends both on a given word's frequency in its language and on its role (function vs. content) in a sentence. Following a presentation of several models explaining these observations we analyze the results of a letter-detection task given to 886 French students from kindergarten to second grade. The purpose of the present study is to determine the moment when the sensitivity to content/function word distinction emerges. The results of this study reveal that even if word frequency plays a role in letter detection, the emergence of an ability to extract sentence structure, along the lines of the structural model of reading, is significantly linked to the initial stages of explicit reading instruction.

De l’impossibilité d’un traitement syntaxique parafovéal à longue portée : une réplique à Foucambert (2008)

Based on results with a new method, Foucambert (2008) argued that syntactic processing can occur as far as 27 characters to the right of the fixation point. In this reply, we demonstrate that the method used by Foucambert was not appropriate. In addition, Foucambert's results did not support his conclusion. We replicate Foucambert's study while monitoring eye movements. Results revealed that subjects’ eye movements were biased to the right of the fixation point. In addition, subjects were unable to engage in syntactic processing of words far in periphery. Taken together, results fit well with current models of eye movements and of the missing-letter effect.

The role of eye movements in the missing-letter effect revisited with the rapid serial visual presentation procedure.

When participants read a text while searching for a target letter, they are more likely to miss the target letter embedded in frequent function words than in less frequent content words. This effect is usually observed with a text displayed normally, for which it has been found that frequent function words are fixated for a smaller amount of time than less frequent content words. However, similar pattern of omissions have been observed with a rapid serial visual presentation procedure in which words appear one at a time. These parallel results would demonstrate that fixation duration per se is not the proximal cause of the missing-letter effect only if eye movements are not made during the rapid serial visual presentation procedure. Therefore, the authors performed eye monitoring during the rapid serial visual presentation procedure. Results revealed that, with a rapid serial visual presentation procedure, participants fixated function and content words for almost the entire presentation duration. It is concluded that eye movements are not the proximal cause of the missing-letter effect.

The effects of different approaches to reading instruction on letter detection tasks in normally achieving and low achieving readers

The present study used two letter detection tasks, the classic missing letter effect paradigm and a single word versus familiar word compound version of this paradigm, to study bottom-up and top–down processes involved in reading in normally achieving as compared to low achieving elementary school readers. The research participants were children in grades first to sixth who had been taught to read by three approaches to reading instruction (ARI): the whole language/global approach, the phonic/synthetic approach or the eclectic approach. Thus, the study attempted to clarify how different ARIs activate these processes in these two types of readers. The main hypothesis was that since low achieving readers rely on top–down processes for word recognition (see, e.g., Stanovich, 1980), the whole language ARI will reduce the difference in bottom-up tasks between them and the normally achieving readers. In the two experiments included in the study, participants were required to perform a letter detection task while reading short texts in Hebrew for comprehension. Contrary to this study hypotheses, the main finding was that the whole language ARI does not compensate for difficulties in bottom-up processes of low achieving readers. Moreover, the results of this study imply that any improvement in basic processes involved in reading proficiency produced by the whole language ARI for both the normal and the low achieving readers dissipates by grade three.

The influence of multiple readings on the missing-letter effect revisited

In searching for a target letter while reading, participants make more omissions when the target letter is embedded in frequent function words than when it is embedded in less frequent content words. According to the guidance-organization (GO) model, this occurs because high-frequency function words are processed faster than low-frequency content words, leaving less time available for letter processing. We tested this hypothesis in three experiments by increasing word-processing speed through text repetition, which should translate into higher omission rates. Participants either read the text and searched for the target letter once or read the text three times and searched for a target letter on all readings or the final reading only. In all the experiments in which participants could not anticipate the target letter to be used, results revealed the presence of a large missing-letter effect that was unaffected by familiarity with the text. In addition, when participants knew from the start the target letter to be used on the final reading, the missing-letter effect was eliminated. Repeated search of the same text for different targets increased omissions equally for function words and content words, but this finding was present even when a new text was used, suggesting that repetition of the search task, rather than familiarity with the text, was responsible.